Surface generation methods can be broadly classified into three categories:
Note that only the boundary method summary makes reference to representing the surface with polygons. This is because whereas parametric and implicit methods can be developed for rendering surfaces directly without the use of a discrete (polygonal) model, such a model is an intrinsic part of boundary methods. However, the parametric and implicit methods used in the Scientific Graphics Project do generate polygonal models. This allows surface data generated by such programs as mesh and solsurf to be used interchangeably as input to VPS.